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BACKGROUND: Ultrasonic coupling agent is indispensable in ultrasonic imaging. The service life and change frequency of the ultrasonic probe is determined by the internal coupling agent of the chosen hydrogel material. Due to defects in the existing gel-formula, after a period of time in use it can cause the surface depression of probes and thus influence the ultrasonic imaging quality. OBJECTIVE: To optimize the gel formula of the coupling agent. METHODS: The amplified synthesis process of polyacrylamide hydrogel was optimized by changing the ratio of monomer concentration to N, N-methylenebisacrylamide crosslinker in the synthesis conditions, and the factors influencing its acoustic properties were explored to meet the technical requirements in the clinical use process. RESULTS AND CONCLUSION: When the monomer concentration was set to 70 g/L and the mass ratio of monomer to crosslinker was 7:1, the polyacrylamide hydrogel was in the best state. The obtained polyacrylamide hydrogel had a stable swelling rate, had a strong ability to keep water and make the volume reduce under the influence of the operating temperature of ultrasound, and its relative amplitude changed less with the change of ultrasonic frequency. The sound attenuation coefficient of polyacrylamide hydrogel would be higher when the frequency of ultrasonic sound source was higher. The changes of monomer concentration would have significant impacts on the acoustic properties of polyacrylamide hydrogel. Therefore, by controlling the monomer concentration ratio, we can prepare the coupling agent that exhibits relatively stable acoustic properties at an optimum concentration and achieves an optimal imaging effect.
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[Objective]To compare and contrast the dosimetry between Tomo planning and BrainLab planning for lung metasta-ses in stereotactic body radiation therapy(SBRT).[Methods]Four Patients with one,two,three and four metastases were selected. The PTV is 2.89 ± 1.15 cm3. Two plannings with total dose of 50 Gy to cover 95% of PTV ,5 Gy/Fraction and 10 fractions were designed using Tomo planning system and BrainLab planning system respectively. The DVH curves of spinal cord ,both lungs and normal tissue were compared. The conformity index andhomogeneityindex were analyzed as well.[Results]The homogeneity index (HI)and conformity index(CI)of the targets in Tomo planning system were 1.0314 ± 0.0700 and 0.687 ± 0.075,respectively. In BrainLab planning system the HI and CI of the targets were 1.0764 ± 0.1241 and 0.571 ± 0.042,respectively. To HI the P value in T test was less than 0.01 and the HI was better in Tomo than BrainLab and so was CI. The dose to spinal cord was higher in BrainLab planning system than that in Tomo. The dose to nomal tissue and both lungs were not different in the two planning systems and V20 of lung is as small as 10%.[Conclusions]For small volume lung metastases which longest diameter were less than 4 cm,the tomotherapy should be better choice.
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Medical intervention is to make use of puncture and catheterization technique for the diagnosis and treatment, relying on the guidance of medical imaging equipment. It is also a new medical branch which is independent of internal medicine and surgery. It is officially named the third largest medical technology. Interventional therapy contains blood vessel intervention and non-vessel intervention. The operation of the catheter and thread in the vessel is the key part of vessel intervention. By comparison it is found that the operation of catheter and thread in the blood vessel is similar to that of the string in the wellbore. Tubular mechanics in oil-gas wells is a mature theoretical mechanics system in the field of Petroleum Engineering. In this paper, the tension-torque model of the tubular mechanics in oil-gas wells is introduced, and the operation of catheter in a simulative vessel is mechanically analyzed with the software of mechanical analysis of drill string in directional wells.
Subject(s)
Humans , Biomechanical Phenomena , Blood Vessels , Pathology , Physiology , Catheterization, Peripheral , Methods , Magnetic Resonance Imaging, Interventional , Radiography, InterventionalABSTRACT
Biometric recognition methods for human identification have received researchers' attention. Seeing that the prominent characteristics of skull biometrics are not affected by facial expression and illumination, we present a new approach compounded of several features. Firstly, comparing the crania included angle; secondly, sampling the edge as the skull feature and analyzing the skull feature in multi-resolution; lastly, calculating the crania cavity area and regularizing the recognition rules. This method supports human identification in cases not only ante mortem but also postmortem.
Subject(s)
Humans , Algorithms , Cephalometry , Methods , Image Interpretation, Computer-Assisted , Image Processing, Computer-Assisted , Methods , Radiography , Skull , Diagnostic ImagingABSTRACT
Skull recognition is a new method of biometrics recognition. A skull recognition algorithm is presented in this paper by Quadratic rational Bezier curve fitting which accurately describes the feature of skull edge; the experiment results based on skull x-ray image show the correctness of this method.
Subject(s)
Humans , Algorithms , Artifacts , Pattern Recognition, Automated , Methods , Radiographic Image Enhancement , Methods , Radiographic Image Interpretation, Computer-Assisted , Methods , Skull , Diagnostic ImagingABSTRACT
Objective To explore the incidence features of neonatal congenital hypothy roidism in Lianyungang area.Methods The heel blood samples dried on filter paper was collected from newborns after 72 hours.Serum thyroid stimulating hormone(TSH)level was detected by Dissociation enhancement lanthanide fluoroimmuno assay(DELFIA).The cases diagnosed were analyszd for the clinicl characters and the incidence features.Result One hundred and fifty-eighet children with CH were diagnosed and the patients lived in 63 towns(streets)(66.3%).The distribution of CH was diffuse in Lianyungang.There was significant difference in incidence of CH between 2007 to June of 2008 and before 2006.Eighty-two patients were examined by thyroid gland color ultrasound,among which there were sixty-eight patients whoes thyroid glands were normal(82.9%)and fourteen patients were unusal(absent,replacement,hypogenesis)(17.1%).A couple of twins(male)and two embryoes from the same parents were screened for CH.Conclusion There are iodine lack(MUI300?g/L)individual among people.The iodine nutrition condition of pregnant women is one of important factor to influence the TSH level of newborns.Neonatal screeing is the only valid means to find patients with CH.
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AIM: To measure and compare the content of glycyrrhizic polysaccharides in Glycyrrhiza in three different growth time. METHODS: The contents of polysaccharides were determined by phenol-sulfuric acid method and by reference to glucose, and wavelenth in spectrophotometer was set at 490 nm. RESULTS: There was difference of the content of the extracted polysaccharides among Glycyrrhiza for 1, 2 and 3 year, amounted to 11.75%, 11.07%, 7.88%, respectively. CONCLUSION: Annual glycyrrhiza appeared to be the appropriat crude drug for polysacchrides content. 1.Colle